This invention relates generally to narrow ware looms of the type where the shuttles are arranged in vertical rows across the width of a batten which is moved vertically in a pattern to one of several positions. There is a warp shed for each row of shuttles and the shuttles move vertically with the batten so that only one shuttle from each row of shuttles is aligned with a warp shed for each position of the batten. The shuttles at each level of the several rows are all driven together as a group through their respective warp sheds and in the same direction. This is accomplished by drive racks, one for each group of shuttles at the several vertical levels. The motion of the racks may be transferred to the shuttles by means of pinions which are interposed between the racks and matching gear teeth on the shuttles as shown, for example, in U.S. Pat. No. 2,132,758 dated Oct. 11, 1938 to F. W. Preston. Since the vertical rows of shuttles are moved in varied patterns, means must be provided for actuating the racks in either direction for each pick of the loom. Sometimes, due to the particular pattern used, the active shuttles will be pushed through the sheds from the same direction on successive picks. Each time the shuttles at one level are driven through their respective sheds from one direction, they must be driven through their respective sheds from the opposite direction the next time that they are in the active position with respect to their respective warp sheds.
To provide the capability of driving the rack which corresponds to the active shuttles in either direction, very elaborate drive mechanisms have been developed. One such drive mechanism is shown in U.S. Pat. No. 1,057,133 dated Mar. 25, 1913 to A. Emery. The drive mechanism shown in this patent is typical of many of the mechanical rack drives which employ positive actuating elements for moving the rack in either direction for each pick. Latching means are employed for operatively connecting the actuating elements to the rack so that only one of the actuating elements will be effective to drive the rack in only one direction. The latching means are arranged so that the position of the rack will determine which latch will effectively connect its actuating mechanism to the rack. The latches themselves are spring loaded and one problem which frequently occurs is that when one of the springs fails, both latches may engage the rack so that both actuating mechanisms try to drive the rack at the same time in opposite directions, resulting in serious damage to various drive elements.
The problems encountered in mechanical drives of the type described above have been overcome by providing fluid pressure rack driving means which drive the racks individually in accordance with a pattern. An example of this type of rack drive is shown in U.S. Pat. No. 2,923,326 dated Feb. 2, 1960 to H. O. Kaffine. However, this type of rack shuttle drive is very complicated and expensive.